Scientists Discover Earliest Trace of Life on Earth in Australia

Scientists have found evidence of bacterial life dating back 3.5 billion years that lived in what is now Australia. This would make these traces of bacteria the earliest known living organisms on Earth and will give scientists clues as to what sort of environment the Earth had during its formative millennium.

The fossilized microbes were found among some of the oldest rock formations on Earth in the remote Pilbara region in Western Australia. Researcher David Wacey, from the University of Western Australia, discussed the discovery with The Telegraph and said he believes that they offer some of the earliest concrete signs of life on Earth:

"There was plenty of life from the 3.4 and 3.43 billion-year-old mark - this is pushing it further back...There are slightly older claims of life in rocks in Greenland - but the rocks there have been so deformed that it is very difficult to tell if what you are seeing was actually there in the first place. With these microbial systems in the Pilbara, you can see these things in the field and under the microscope. You can see how the bacteria were interacting with the sediment they were living on."

While the actual cells of the microbes cannot be seen, they left imprints on the rock due to large gatherings of the microorganisms called mats. Wacey describes how these very old and very small fossils still managed to make their mark billions of years later:

"We don't see the microbe themselves but we large scale structures that the microbes constructed before they died...We see tufts and wrinkles and - when we look down the microscope - we see filaments tangled in sand grains. We are also seeing organic material which are the actual microbes but they are decomposed to the point that we cannot see an actual cell. You just see a mass of carbon-rich material." The team of scientists from Australia and the United States believes the findings may help with the search for life on other planets."

Wacey was excited by this discovery and spoke at length about how these fossils could reveal more about life is formed not just on Earth, but elsewhere in the universe.

"There are applications for searching for life elsewhere and knowing what to look for...These microbial mats could be seen by a Mars rover... It also helps with our understanding of when life first evolved and what sort of environment it evolved in and putting firm dates on when some pretty important things happened. Ultimately, we are looking for when that soup of chemicals became something that could be called life," said Wacey.